P-Q THEORY AND APPARENT POWER CALCULATION FOR ACTIVE FILTERING

Autor/autori: Alexandru BITOLEANU, Mihaela POPESCU, Vlad SURU

Rezumat: Lucrarea sugereaza doua noi definitii ale puterii aparente pe baza teoriei p-q (teoria puterii aparente complexa instantanee). Astfel, se pun in evidenta componentele puterii neutile si relatia de cuadratura existenta intre puterile aparenta, activa, reactiva si deformanta. Multe studii de caz arata ca exista o corespondenta intre relatiile propuse si cele exsistente in literatura. Astfel, daca tensiunea este sinusoidala, relatiile propuse conduc la valori egale ale puterii aparente, ca si relatiile propuse de Bucholtz si Czarnecki. In conditii de tensiune nesinusoidala, prima relatie propusa conduce la valori mai mari. A doua relatie conduce, intotdeauna, la aceleasi valori ale puterii aparente ca si relatiile propuse de Bucholtz si Czarnecki. Semnificativ este ca relatia recomandata de IEEE (The IEEE Standard Dictionary of Electrical and Electronics Terms, 6th), conduce la rezultate eronate daca sarcina este dezechilibrata si se aduc noi argumente in acest sens

Cuvinte cheie: Puterea aparenta complexa instantanee, putere aparenta, putere deformanta, factor de putere


Abstract: This paper suggests a new two definitions of apparent power based on the instantaneous p-q power theory. The component corresponding to the non-useful power and the quadratic relationship between apparent, active, reactive and nonuseful powers are also highlighted. A lot of case-studies draw a parallel between the results according to the well-known definitions gathered from previous literature and the results based on the new expression. It is shown that, under sinusoidal and balanced conditions, all definitions of the apparent power lead to the same results. However, in the case of sinusoidal unbalanced situations, the results based on the new definition are identical only with those corresponding to Buchholz’s and Czarnecki’s definitions. In contrast, under non-sinusoidal conditions, one of the suggested definitions leads to higher values of the apparent power. The second suggested definition leads to the same results as relations proposed by Bucholtz and Czarnecki, for all analyzed cases. It stressed that the relation recommended by IEEE (IEEE Standard Dictionary of the Electrical and Electronics Terms, 6th), leads to erroneous results if the load is unbalanced and new arguments are brought in this regard.

Keywords: Instantaneous Complex Apparent Power, Apparent Power, Distortion Power, Power Factor

 

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